Promax US TV EXPLORER 2 User Manual página 61

USER'S MANUAL. US TV EXPLORER II
As well as the video carrier / noise level ratio (C/N) (43.7 dB in previous figure),
the frequency or channel (depending on the tuning mode selected) and the level of the
video carrier and video/audio ratio are also shown. When representing the spectrum by
means of pressing [13] key, the NOISE cursor is automatically positioned to a side
of the carrier tuned. That is, the cursor will indicate the point where the value of the
noise is lower, whenever the C/N(AUTO) option is selected from the PREFERENCES
[22] menu. If the C/N(MANUAL) option has been activated the frequency where
noise level will be measured will correspond to the position of the vertical discontinuous
green-coloured cursor that appears in the spectrum graph
In order to modify this frequency, press the measurement configuration
[17] key, to accede to the CONFIGURATION menu. By turning the rotary selector [1],
locate the NOISE cursor on the position of the marker using
option (see section "5.16.1 Markers") or directly enter the value of the new noise
frequency by means of
NOISE FREQ
70
60
50
40
30
CH:
Figure 28.- NOISE cursor. C/N (MANUAL)
When measuring channels in the satellite band or digital channels, to measure
the C/N ratio correctly, the bandwidth of the channel must be defined previously, using
the Channel BW option on the Measurements Configuration menu that appears
when pressing [17] key.
10/2007
NOISE FREQ. TO MARKER
option.
FREQ: 650.00 MHz
C/N REF: 16.5 dB
43 SPAN: 32 MHz
[13].
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